Population genetics of fire salamanders in a pre-Alpine urbanized area (Salzburg, Austria)

Habitat alteration has been identified as one of the major causes of amphibian decline. In this study, the genetic structure of seven fire salamander subpopulations in the urbanized area of Salzburg (Austria) was investigated based on seven polymorphic microsatellite loci. We combined Bayesian clustering approaches (STRUCTURE, TESS) with the traditional F-statistics to evaluate the effect of potential barriers on gene flow. Both clustering approaches suggested that all sampled individuals belong to a single genetic pool (K = 1). While no clear-cut sign of genetic differentiation could be detected, pairwise FST-values suggest that the city of Salzburg potentially has an effect, but the effect of the highway leading to it remains hypothetical. This study corroborates that habitat alteration effects might take several generations before leading to isolated genetic pools, particularly in long-lived species. Such delayed effects have to be taken into account for population genetic analyses, in particular when it comes to conservation management and planning.